Fifth wheel coupling for tractor-trailer vehicle

ABSTRACT

A fifth wheel coupling for a tractor-trailer vehicle including a fifth wheel plate to be rockably mounted on the tractor, a turntable plate to be rotatably mounted on the trailer, means releasably joining the plates in coupled relation, wherein the table plate rests on and is coupled to the wheel plate, and mating conduit coupling parts mounted on the plates for relative movement into and from mating engagement upon relative movement of the plates into and from coupled relation. The mating conduit coupling parts may constitute an electrical coupling for transmitting electrical power between the tractor and trailer and a hose coupling for transmitting pressure fluid, such as braking air, between the tractor and trailer.

United States Patent Roesies 1 1 Apr. 4, 1972 [54] FIFTH WHEEL COUPLINGFOR TRACTOR-TRAILER VEHICLE David J. Roesies, 16127 Francisquito Ave.,La Puente, Calif. 91744 22 Filed: Apr. 17,1970

211 App]. 190.; 29,546

[72] Inventor:

2,142,748 1/1939 Fontaine ..280/434 Primary Examiner-Leo FriagliaAttorney-Boniard I. Brown 57 ABSTRACT A fifth wheel coupling for atractor-trailer vehicle including a fifth wheel plate to be rockablymounted on the tractor, a turntable plate to be rotatably mounted on thetrailer, means relcasably joining. the plates in coupled relation,wherein the table plate rests on and is coupled to the wheel plate, andmating conduit coupling parts mounted on the plates for relativemovement into and from mating engagement upon relative movement of theplates into and from coupled relation. The mating conduit coupling partsmay constitute an electrical coupling for transmitting electrical powerbetween the tractor and trailer and a hose coupling for transmittingpressure fluid. such as braking air, between the tractor and trailer.

8 Claims, SDrawing Figures FIFTH WHEEL COUPLING FOR TRACTOR-TRAILERVEHICLE BACKGROUND OF THE INVENTION 1. Field of the Invention Thisinvention relates generally to tractor-trailer vehicles and moreparticularly to a novel fifth wheel coupling for such vehicles.

2. Prior Art A tractor-trailer vehicle is a cargo hauling vehicle havinga self-propelled towing unit, referred to as a tractor, a followingcargo carrier, referred to as a semi-trailer, coupled to the tractor,and in some cases, a second cargo carrier, referred to as a trailer,coupled to the semi-trailer. The semi-trailer, referred to in thisdisclosure simply as a trailer, is connected to the tractor by means ofa fifth wheel coupling. This coupling serves the dual function oftransmitting towing loads between the tractor and trailer and verticallysupporting the front end of the trailer on the tractor. When detachedfrom the tractor, the front end of the trailer is supported on dependingstruts, mounting, in some cases, small ground engaging rollers.

A conventional fifth wheel coupling for a tractor-trailer vehicle has awheel plate rockably mounted on the rear of the tractor on a traversepivot axis of the tractor, and a king pin depending from the undersideof the trailer for rotatable coupling engagement within a centralcoupling socket in the wheel plate. Extending rearwardly through thewheel plate from its coupling socket through the rear edge of the plateis a slot through which the trailer king pin may undergo relativemovement into and from the socket. A retractable lock bolt extendsacross the end of the slot adjacent the coupling socket to releasablylock the king pin in the socket. The wheel plate is so oriented thatwhen the trailer is detached from the tractor,

the plate rotates on its pivot axis to an inclined position wherein theplate slopes upwardly in the forward direction.

When coupling a tractor to a trailer, the tractor is backed toward thetrailer to locate the wheel plate of the fifth wheel coupling below andin supporting contact with the front end of the trailer in a manner suchthat the king pin on the trailer enters the coupling socket in the wheelplate through its slot. The lock bolt in the wheel plate is thenextended to lock the king pin in the socket.

In addition to the mechanical connection between tractor and trailerprovided by the fifth wheel coupling, a tractortrailer vehicle has anumber s service conduits for transmitting electrical power and pressurefluid, such as air or hydraulic fluid, between the tractor for operatinglights, brakes, and the like on the tractor. These conduits containservice couplings which must be disengaged when the tractor is uncoupledfrom the trailer and reengaged when the tractor is coupled to thetrailer. A major disadvantage of the existing vehicles resides in thefact that the service couplings must be disengaged and reengagedindividually by hand. As a consequence, coupling and uncoupling of atractor-trailer vehicle is quite a tedious and time consuming operation.

SUMMARY OF THE INVENTION The present invention avoids the abovedisadvantage of the existing trailer-tractor vehicles by providing animproved fifth wheel coupling for such a vehicle embodying electricaland fluid service couplings which automatically engage and disengageupon coupling and uncoupling of the tractor and trailer. The improvedfifth wheel coupling has a fifth wheel plate to be mounted on thetractor and a rotating turntable or turntable plate, hereafter referredto simply as a table plate, to be rotatably mounted on the trailer of atractor-trailer vehicle. Depending from the underside of the table plateon its rotation axis is a king pin for coupling engagement within acentral coupling socket in the wheel plate. The wheel plate has a slotthrough which the king-pin undergoes relative movement into and from thesocket during relative movement of the wheel plate and table plate toand from coupled relation. The kingpin is releasably locked on thesocket by the usual retractable lock bolt.

According to one feature of the invention, the fifth wheel coupling isequipped with electrical and fluid service couplings including matingcoupling parts which are mounted on the wheel plate and table plate toenter into mating engagement upon relative movement of the plates intocoupled relation. Relative movement of the plates from coupled relationdisengages the service couplings. Such automatic engagement anddisengagement of the service couplings requires alignment of the tableplate in a predetermined angular position on its rotation axis relativeto the wheel plate during coupling and uncoupling of the plates.Moreover, retention of the service couplings in their engaged relationduring travel of the tractortrailer vehicle requires interlocking of thewheel and table plate against relative rotation when in coupledrelation. According to a second important feature of the invention, thewheel and table plates are equipped with coacting alignment means forthus aligning and interlocking the plates.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of atractor-trailer vehicle embodying the fifth wheel coupling of theinvention;

FIG. 2 is an enlarged section taken on line 2-2 in FIG. 1;

FIG. 3 is a section view taken at line 3-3 in FIG. 2;

FIG. 4 is a section view taken at line 3-in FIG. 3; and

FIG. 5 is a section view taken at line 5-5 in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT The drawings illustrate atractor-trailer vehicle including a fifth wheel coupling 12 according tothe invention for coupling the vehicle tractor 14 to the vehicle trailer16.

Coupling 12 includes a so-called fifth wheel in the form of a wheelplate 18 having a central coupling socket 20 and a tapered slot 22extending from the socket through the normally rear edge of the plate.Mounted on the under side of the wheel plate is a retractable lock bolt24. Lock bolt 24 is supported on bearing 26 for longitudinal movement,transverse to the slot 22, between an extended locking position and aretracted position. In its locking position, the bolt extends across theforward end of the slot 22, that is, the end adjacent the couplingsocket 20, and through openings on boundary flanges 32 along the edgesof the slot. In its retracted position, the bolt is withdrawn clear ofthe slot.

Below the wheel plate 18 is a mounting bracket to which the plate ispivotally attached by a hinge pin in 33, for rocking of the platerelative to the bracket on a pivot axis intersecting at right angles theaxes of the coupling socket 20 and the slot 22. The wheel plate 18 isinstalled in the tractor 14 by rigidly attaching the plate mountingbracket 30 to the rear of the vehicle frame. When thus installed, thepivot axis of the plate extends laterally of the tractor and the plateslot 22 extends rearwardly from the plate coupling socket 20.

In addition to the wheel plate 18, the fifth wheel coupling 12 includesa turntable in the form of a rotary plate 34, herein referred to as atable plate, on the trailer 16. Wheel plate 34 is circular in shape andis rotatably attached to the normally underside of a mounting plate 36by means of a bearing ring 38. This bearing ring is rigidly fixed to themounting plate 36 and has a flange 40 overlapping the edge of the tableplate. The bearing ring and mounting plate support the table plate forturning on its central axis. Rigidly joined to and depending from theunderside of the table plate on its central rotation axis is a king-pin42 having a circumferential locking flange 44. The table plate 34 ismounted on the trailer 16 by rigidly securing the mounting plate 36 tothe trailer.

The drawings illustrate the fifth wheel plate 18 and table plate 34assembled in coupled relation to connect the tractor 14 to the trailer16. In this coupled relation, the table plate king-pin 42 is containedwithin the wheel plate socket 20 and the lock bolt 24 is extended acrossthe wheel plate slot 22 to lock the stud in the socket. The table plate34 rests on the wheel plate 18 to vertically support the front end ofthe trailer 16 on the tractor 14. Uncoupling of the tractor from thetrailer is accomplished by retracting the lock bolt 24 and driving thetractor from under the trailer while the front end of the trailer issupported on its supporting struts 46. During this uncoupling motion ofthe tractor, the table plate king-pin 42 emerges from the wheel platesocket through the wheel plate slot 22. Recoupling of the tractor andtrailer is accomplished by reversing this procedure.

Extending between the tractor 14 and trailer 16 are electrical conduits48 for transmitting electrical current and air conduits 50 forconducting brake operating air between the tractor and trailer. Theseconduits include couplings 52 and 54, respectively, which must bedisengaged when the tractor and trailer are uncoupled and engaged whenthe tractor and trailer are coupled.

According to one important feature of the invention, the conduitcouplings 52, 54 are engaged and disengaged automatically upon relativemovement of the tractor 14 and trailer 16 into and from coupledrelation. To this end, each electrical conduit coupling 52 has a firstcoupling part 52a mounted on the wheel plate 18 and a second couplingpart 52b mounted on the table plate 34. Similarly, each air conduitcoupling 54 has a first coupling part 54a mounted on the wheel plate anda second coupling part 5411 mounted on the table plate. Air couplings 54are located in the plane of the wheel plate 18. The electrical couplingsare located directly below the air couplings. The two parts of eachcoupling are so located on their respective plates that the parts arecoaxially aligned when the table plate 34 occupies its angular positionof FIG. 2 relative to the wheel plate 18. It will now be understood,therefore, that the corresponding coupling parts are arranged forrelative movement into and from mating engagement during relativecoupling and uncoupling movement of the tractor 14 and trailer 16 withthe table plate 18 oriented in its angular position of FIG. 2.

One air conduit coupling 54 is illustrated in enlarged detail in FIG. 5.The wheel plate part 54a of this coupling is a male part having atubular stem 56 terminating in a rear conical tip 58 surrounded by anO-ring 60. Stem 56 is slidably supported in a flange 62 rigid on thewheel plate 18. A spring 64 urges the coupling part 54a rearwardly.Threaded on the front end of the stem 56 is an adjustable stop nut tolimit rearward extension of the part 54a when the coupling 54 isdisengaged. The table plate coupling part 54b is a female part having astem 66 terminating in a forwardly opening conical socket 68 forreceiving, in mating engagement, the conical tip 58 on the male couplingpart 54a. Stern 66 is firmly attached to a flange 70 rigid on the tableplate 34.

From the above description of the air coupling 54, it is evident thatits coupling parts 54a, 54b are adapted to undergo relative movementinto and from mating engagement during coupling and uncoupling of thetractor 14 and trailer 16. During engagement of the coupling, the malecoupling part 54a yields rearwardly against the action of spring 64following engagement of its tip 58 in the socket 68 of the female part54b, such that the spring retains the parts in finally coupled relation.In this regard, it will be understood that the coupling spring issufficiently strong to prevent separation of the coupling parts underthe action of the maximum braking air pressure in the coupling.

One electrical coupling 52 is also detailed in FIG. 5. The couplingparts 52a, 54a are mounted on flanges 62 and 72 rigid on the wheel plate18 and table plate 34, respectively, as shown in FIG. 5.

According to a further feature of the invention, the fifth wheelcoupling 12 is equipped with alignment means 74 for automaticallyorienting or aligning the rotary table plate 34 in its angular positionof FIG. 2, wherein the conduit couplings 52, 54 are conditioned forautomatic engagement, upon relative movement of the table plate andwheel plate 18 into coupled relation and for interlocking the platesagainst relative rotation when assembled in coupled relation to preventdisengagement of the conduit couplings during travel. Alignment means 74comprise a pair of guide bars 76 rigidly mounted on the wheel plate inparallel relation to the centerline of the wheel plate slot 22 and theaxes of the wheel plate coupling parts 52a, 54a. These bars straddle thelatter coupling pans and are rigidly joined to their mounting flanges 62and additional flanges 78 on the wheel plate. The alignment meanscomprise a second pair of guide bars 80 rigid on the rotary table plate34. These latter bars straddle and parallel the axes of the table platecoupling parts 52a, 54b and are spaced to straddle, in sliding relation,the wheel plate guide bars 76. As shown in FIG. 2, the forward ends ofthe table plate guide bars 80 turn outwardly at slight angles tofacilitate entrance therebetween of the wheel plate guide bars 76 duringrelative movement of the plates into coupled relation. It will now beunderstood that during movement of the tractor-trailer vehicle 10,rotation in the fifth wheel coupling 12 during turning involves rotationof the table plate 34 relative to the trailer 16.

One unique advantage of the present fifth wheel coupling resides in thefact that it permits either the tractor 14 or trailer 16 of atractor-trailer vehicle equipped with the coupling to be coupled to atrailer or tractor, as the case may be, equipped with a conventionalfifth wheel coupling.

What is claimed is: l. A fifth wheel coupling for a tractor-trailervehicle comprising:

a fifth wheel plate having a central axis, means for mounting said wheelplate on said tractor, a table plate having a central rotation axis,means for rotatably mounting said table plate on said trailer forturning on said rotation axis, coacting releasable connecting means onsaid plates releasably joining said plates in coupled relation whereinsaid central axes coincide with said table plate rests on said wheelplate, said connecting means comprising a king-pin depending from theunderside of said table plate on said rotation axes thereof, a centralcoupling socket in said wheel plate on said central axes thereof,receiving said king-pin, a radial slot in said wheel plate extendingfrom said socket through the circumference of said wheel plate, and aretractable lock bolt extending laterally across the end of said slotadjacent said socket for releasably locking said king-pin in saidsocket, said plates being relatively movable along given direction linesinto and from coupled relation, and the relative movement of saidking-pin with respect to said wheel plate during relative movement ofsaid plate along said direction lines into and from coupled relationoccurring lengthwise through said slot, said lock bolt being retractableto permit relative movement of said king-pin into andfrom said socketthrough said slot, mating conduit coupling parts mounted on said plates,respectively, for relative movement into and from mating engagement uponrelative movement of said plates along said direction lines into andfrom coupled relation, coacting alignment means on said plates,respectively, for

aligning said table plate in a predetermined angular position on itsrotation axis relative to said wheel plate upon relative movement ofsaid plates along said direction lines into coupled relation andinterlocking said plates against relative rotation when in coupledrelation, said alignment means comprising guides on said wheel plateparalleling the longitudinal centerline of said slot and guides on saidtable plate engageable with said wheel plate guides during relativemovement of said plates along said directions into and from coupledrelation, and

said coupling parts being disposed to mate upon relative movement ofsaid plates along said direction lines into coupled relation with saidtable plate aligned in said predetermined angular position.

2. A fifth wheel coupling according to claim 1 wherein:

said conduit coupling parts comprise an electrical coupling.

3. A fifth wheel coupling according to claim 1 wherein:

said conduit coupling parts comprise a hose coupling.

4. A fifth wheel coupling according to claim 1 including:

coacting alignment means on said plates, respectively, for

aligning said table plate in a predetermined angular position on itsrotation axis relative to said wheel plate upon relative movement ofsaid plates along said direction lines into coupled relation andinterlocking said plates against relative rotation when in coupledrelation, and

said coupling parts being disposed to mate upon relative movement ofsaid plates along said direction lines into coupled relation with saidtable plate aligned in said predetermined angular position.

5. A fifth wheel coupling according to claim 1 wherein:

said guides comprise guide bars.

6. A fifth wheel coupling according to claim 5 wherein:

the axis of said wheel plate coupling part parallels said wheel plateguide bars and the axis of said table plate coupling part parallels saidtable guide bars.

7. A fifth wheel coupling according to claim 6 wherein:

one'coupling part has a tapered coupling socket and the other couplingpart has a tapered end engageable in said tapered coupling socket.

8. A fifth wheel coupling for a tractor-trailer vehicle comprising:

a fifth wheel plate having a central axis,

means for mounting said wheel plate on said tractor,

a table plate having a central rotation axis,

means for rotatably mounting said table plate on said trailer forturning on said rotation axis,

coacting releasable connecting means on said plates releasably joiningsaid plates in coupled relation wherein said central axes coincide withsaid table plate rests on said wheel plate, said connecting meanscomprising a king-pin depending from the underside of said table plateon said rotation axes thereof, a central coupling socket in said wheelplate on said central axes thereof, receiving said king-pin, a radialslot in said wheel plate extending from said socket through thecircumference of said wheel plate, and means for releaseably lockingsaid king-pin in said socket,

said plates being relatively movable along given direction lines intoand from coupled relation, and the relative movement of said king-pinwith respect to said wheel plate during relative movement of said platealong said direction lines into and from coupled relation occurringlengthwise through said slot, mating conduit coupling parts mounted onsaid plates, respectively, for relative movement into and from matingengagement upon relative movement of said plates along said directionlines into and from coupled relation,

coacting alignment means on said plates, respectively, for

aligning said table plate in a predetermined angular position on itsrotation axis relative to said wheel plate upon relative movement ofsaid plates along said direction lines into coupled relation andinterlocking said plates against relative rotation when in coupledrelation, said alignment means comprising guides on said wheel plateparalleling the longitudinal centerline of said slot and guides on saidtable plate engageable with said wheel plate guides during relativemovement of said plates along said directions into and from coupledrelation, and said coupling parts being disposed to mate upon relativemovement of said plates along said direction lines into coupled relationwith said table plate aligned in said predetermined angular position.

1. A fifth wheel coupling for a tractor-trailer vehicle comprising: afifth wheel plate having a central axis, means for mounting said wheelplate on said tractor, a table plate having a central rotation axis,means for rotatably mounting said table plate on said trailer forturning on said rotation axis, coacting releasable connecting means onsaid plates releasably joining said plates in coupled relation whereinsaid central axes coincide with said table plate rests on said wheelplate, said connecting means comprising a king-pin depending from theunderside of said table plate on said rotation axes thereof, a centralcoupling socket in said wheel plate on said central axes thereof,receiving said king-pin, a radial slot in said wheel plate extendiNgfrom said socket through the circumference of said wheel plate, and aretractable lock bolt extending laterally across the end of said slotadjacent said socket for releasably locking said king-pin in saidsocket, said plates being relatively movable along given direction linesinto and from coupled relation, and the relative movement of saidking-pin with respect to said wheel plate during relative movement ofsaid plate along said direction lines into and from coupled relationoccurring lengthwise through said slot, said lock bolt being retractableto permit relative movement of said king-pin into and from said socketthrough said slot, mating conduit coupling parts mounted on said plates,respectively, for relative movement into and from mating engagement uponrelative movement of said plates along said direction lines into andfrom coupled relation, coacting alignment means on said plates,respectively, for aligning said table plate in a predetermined angularposition on its rotation axis relative to said wheel plate upon relativemovement of said plates along said direction lines into coupled relationand interlocking said plates against relative rotation when in coupledrelation, said alignment means comprising guides on said wheel plateparalleling the longitudinal centerline of said slot and guides on saidtable plate engageable with said wheel plate guides during relativemovement of said plates along said directions into and from coupledrelation, and said coupling parts being disposed to mate upon relativemovement of said plates along said direction lines into coupled relationwith said table plate aligned in said predetermined angular position. 2.A fifth wheel coupling according to claim 1 wherein: said conduitcoupling parts comprise an electrical coupling.
 3. A fifth wheelcoupling according to claim 1 wherein: said conduit coupling partscomprise a hose coupling.
 4. A fifth wheel coupling according to claim 1including: coacting alignment means on said plates, respectively, foraligning said table plate in a predetermined angular position on itsrotation axis relative to said wheel plate upon relative movement ofsaid plates along said direction lines into coupled relation andinterlocking said plates against relative rotation when in coupledrelation, and said coupling parts being disposed to mate upon relativemovement of said plates along said direction lines into coupled relationwith said table plate aligned in said predetermined angular position. 5.A fifth wheel coupling according to claim 1 wherein: said guidescomprise guide bars.
 6. A fifth wheel coupling according to claim 5wherein: the axis of said wheel plate coupling part parallels said wheelplate guide bars and the axis of said table plate coupling partparallels said table guide bars.
 7. A fifth wheel coupling according toclaim 6 wherein: one coupling part has a tapered coupling socket and theother coupling part has a tapered end engageable in said taperedcoupling socket.
 8. A fifth wheel coupling for a tractor-trailer vehiclecomprising: a fifth wheel plate having a central axis, means formounting said wheel plate on said tractor, a table plate having acentral rotation axis, means for rotatably mounting said table plate onsaid trailer for turning on said rotation axis, coacting releasableconnecting means on said plates releasably joining said plates incoupled relation wherein said central axes coincide with said tableplate rests on said wheel plate, said connecting means comprising aking-pin depending from the underside of said table plate on saidrotation axes thereof, a central coupling socket in said wheel plate onsaid central axes thereof, receiving said king-pin, a radial slot insaid wheel plate extending from said socket through the circumference ofsaid wheel plate, and means for releaseably locking said king-pin insaid socket, said plates being Relatively movable along given directionlines into and from coupled relation, and the relative movement of saidking-pin with respect to said wheel plate during relative movement ofsaid plate along said direction lines into and from coupled relationoccurring lengthwise through said slot, mating conduit coupling partsmounted on said plates, respectively, for relative movement into andfrom mating engagement upon relative movement of said plates along saiddirection lines into and from coupled relation, coacting alignment meanson said plates, respectively, for aligning said table plate in apredetermined angular position on its rotation axis relative to saidwheel plate upon relative movement of said plates along said directionlines into coupled relation and interlocking said plates againstrelative rotation when in coupled relation, said alignment meanscomprising guides on said wheel plate paralleling the longitudinalcenterline of said slot and guides on said table plate engageable withsaid wheel plate guides during relative movement of said plates alongsaid directions into and from coupled relation, and said coupling partsbeing disposed to mate upon relative movement of said plates along saiddirection lines into coupled relation with said table plate aligned insaid predetermined angular position.